The present invention relates, in general, to electronics, and more particularly, to methods of forming semiconductor devices and structure.
In the past, the electronics industry utilized various methods and devices to control high value or large input voltages in order to provide controlled output voltages and currents. One example of such a device, referred to as an off-line bootstrap startup circuit, was disclosed in U.S. Pat. No. 5,477,175 which was issued to Tisinger et al on Dec. 19, 1995 and which is hereby incorporated herein by reference. The bootstrap startup circuit received a large input voltage and produced an output current that charged a capacitor and generated an output voltage. However, many applications required a sequence of currents that could be controlled to charge the capacitor and form the output voltage. However, using multiple bootstrap startup circuits increased the manufacturing cost and complexity of the resulting semiconductor products and of applications using the products.
Accordingly, it is desirable to have a startup circuit that can receive an input voltage having a high voltage value and produce a sequence of currents from the input voltage, and that reduces manufacturing costs.
For simplicity and clarity of illustration, elements in the figures are not necessarily to scale, and the same reference numbers in different figures denote the same elements. Additionally, descriptions and details of well known steps and elements are omitted for simplicity of the description. As used herein current carrying electrode means an element of a device that carries current through the device such as a source or a drain of an MOS transistor or an emitter or a collector of a bipolar transistor, and a control electrode means an element of the device that controls current through the device such as a gate of an MOS transistor or a base of a bipolar transistor.